1. Field of the Invention
The present invention relates to a cutting device for a sewing system of the general type which has a material clamp for transporting the sewing material past the needle, two wedge-shaped knives arranged under the work table at a cutting point downstream from the needle for producing gusset cuts in the material, and a slit-shaped recess in the work table for passage of the wedge-shaped knives.
The invention relates more particularly to a device for providing more reliable clamping of the sewing material while the gusset cuts are being made, to provide better control over the locations of the gusset cuts.
The invention may also stretch or tension the material transversely to the direction in which it is transported by the material clamp.
2. Background Art
Devices for producing cuts at the ends of pocket cuts, particularly in the case of piped pocket cuts, are known from U.S. Pat. No. 4,341,169 and Federal Republic of Germany Patent 34 04 758 (which corresponds to U.S. Pat. 4,589,358). All prior art materials mentioned herein are expressly incorporated by reference.
At a feed station, the piping strip is placed mechanically on the material being sewn. A fabric clamp descends onto the piping strip and clamps it onto the material being sewn. The two parts are then brought to the sewing point where the piping strip is sewn to the material by means of a double-needle sewing machine. At the same time, the pocket opening is cut by means of a knife arranged between the two needles.
At a cutting point downstream from the sewing point, two wedge-shaped knives are arranged below the work table, and after the sewing operation is completed, the wedge-shaped knives make gusset cuts at the ends of the lengthwise cut. These gusset cuts are necessary so that the pocket opening of the finished article of clothing does not develop folds caused by several superimposed layers of material.
Since the wedge-shaped knives move upward past the top of the work table, it is difficult to locate the cuts at a reproducible place, in the case of thin material. Due to its elasticity, the material is pushed away from the work table before it is cut to a greater or lesser extent, by the upward movement of the knives.